Migraine headache is estimated to effect 17.6 of females and 5.7% of males in the United States. Recent epidemiologic studies in young adults, including our own study of more than 1,000 randomly selected 21 to 30 years old members of a large HMO, found that migraine is associated with increased odds for psychiatric comorbidity, primarily major depression and anxiety disorders. The high prevalence of migraine, especially in women, and the disabling consequences of the psychiatric disorders associated with it constitute a strong rationale for community-based research on psychiatric comorbidity in migraine. We propose to conduct a longitudinal community based study to test prospectively hypotheses concerning the psychiatric comorbidity associated with migraine. The psychiatric disorders of interest are major depression, anxiety disorders and psychoactive substance use disorders. Suicide attempts and ideation will be included as well. The study will extend previous research on this issue to a wider age range (25-55) and will test whether the odds for psychiatric disorders are higher in migraine with aura vs. migraine without aura. In addition, suspected risk factors for major depression in persons with migraine, identified in our previous research, will be examined, including prior history of coexisting anxiety disorder, severity of headache pain, and functional impairment. A random digit dialing telephone survey will be used to ascertain the presence of active migraine (at least one attack in last year) within a sample of 4,500 persons, 25 to 55 years of age. Using 15% as an estimate, 675 migraineurs will be identified. An equal number of controls will be selected, frequently matched on age and sex from an estimated pool of 2,300 persons with no history of severe headaches. A subset of 405 persons with severe, tension headaches will be identified for exploring hypotheses about mechanisms in migraine - psychopathology comorbidity. Two wave, two years apart, assessments will be conducted in face-to-face interviews in respondents' homes and will use a structured diagnostic interview to measure psychiatric and substance use disorders, severity of headache pain, functional impairment and other variables of interest. Data analysis plan is designed to test hypotheses about the extent to which change in the dependent variables during the follow-up depends upon factors measured at baseline.